The overall goal of this Core is to link the Atlanta HIV/AIDS clinical investigators into a network that will support research in the behavioral, therapeutic, virologic, immunologic, and pharmacologic aspects of HIV/AIDS. The Atlanta CFAR Clinical Core will provide well characterized clinical specimens to Atlanta/Emory CFAR investigators for clinical, behavioral, virologic, immunologic, and pharmacologic studies. The core will consist of 1) a database of 400 patients who volunteer to participate in the Core; 2) a repository of stored specimens from selected individuals in the database with specific characteristics; 3) capability of located individuals to provide specific specimens upon request and delivering those specimens to the requesting investigator. The Clinical Core will be located at four sites: the Ponce de Leon Center, the AIDS Research Consortium of Atlanta, the Crawford Long Hospital of Emory University, and the Atlanta VAMC Center for Excellence in AIDS Care. HIV-infected volunteers will be recruited, evaluated, and enrolled into the cohort at all four sites. At entry a demographic record will be established for each patient; these records will be updated every three months. From these 400 patients, a subgroup of 200 patients will be selected and asked to contribute serum and peripheral blood mononuclear cells to a specimen repository every three months.